Are FoxP2, Otx1 and FoxO3 candidates for deep homology in weakly electric fish?

Abstract

Event Abstract Back to Event Are FoxP2, Otx1 and FoxO3 candidates for deep homology in weakly electric fish? Erik Harvey-Girard1*, Anna Catarina Giassi1 and Leonard Maler1 1 University of Ottawa, Cellular and Molecular Medecine, Canada During embryological development the teleost telencephalon undergoes eversion while tetrapod telencephalon goes through evagination. This difference in development has caused major problems to establish any homology between teleost and tetrapod telencephalon. We recently determined the extrinsic and intrinsic neuronal connections of weakly electric fish (Apteronotus leptorhynchus) telencephalon. In particular, we observed that the dorsocentral division of the pallium (DC) contains glutamatergic spiny neurons that receive inputs from the dorsolateral (DL) pallium (homologous to the tetrapod hippocampus) and project to midbrain sensory nuclei (optic tectum, torus semicircularis) involved in visual and electrosensory signal processing. This pattern of connectivity is similar to that of the spiny glutamatergic pyramidal cells within the deep neocortical layers (V/VI). We wondered if there was a deep homology between teleost DC neurons and tetrapod neocortical neurons. To test that hypothesis, we investigated some molecular markers from deep neocortical layers (FoxP2 and Otx1) and hippocampus (FoxO3). First, we have cloned the apteronotid homologs of FoxP2, Otx1 and FoxO3. There was, in the case of all three genes, good similarity between the apteronotid and human amino acid sequences: FoxP2 – 78%, Otx1 – 54%, FoxO3 – 71%. The functional domains of these genes were conserved to a far greater extent – on average: FoxP2 – 89%, Otx1 – 76%, FoxO3 – 82%. This led us to hypothesize that the cellular functions of these genes may also be conserved. We then used in situ hybridization to examine the distribution of the mRNA transcripts of these genes in the apteronotid telencephalon. We found that AptFoxP2 and AptOtx1 transcripts were expressed predominantly in DC, with only a few weakly labeled neurons in DL. In contrast, we found that most neurons in DL strongly expressed AptFoxO3 mRNA, while there was only weak expression in a small number of cells within DC. Together with our previous hodological and anatomical data, these data suggest a deep homology exists between teleost DC and tetrapod neocortical deep layers. Furthermore, in accordance with previous studies in other teleosts, our data suggest that there is also a direct homology between teleost DL and mammal hippocampus. Acknowledgements CIHR Keywords: Apteronotus leptorhynchus, Deep homology, dorsal telencephalon, pallium, FOXO3, FoxP2, Hippocampus, Neocortex, Otx1 Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster Presentation (see alternatives below as well) Topic: Evolution Citation: Harvey-Girard E, Giassi A and Maler L (2012). Are FoxP2, Otx1 and FoxO3 candidates for deep homology in weakly electric fish?. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00089 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 18 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Erik Harvey-Girard, University of Ottawa, Cellular and Molecular Medecine, Ottawa, Ontario, K1H 8M5, Canada, erikhg@uottawa.ca Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Erik Harvey-Girard Anna Catarina Giassi Leonard Maler Google Erik Harvey-Girard Anna Catarina Giassi Leonard Maler Google Scholar Erik Harvey-Girard Anna Catarina Giassi Leonard Maler PubMed Erik Harvey-Girard Anna Catarina Giassi Leonard Maler Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.